The ad, produced by the Senate campaign of John Spencer, accuses Clinton of opposing national security programs, including the USA Patriot Act and a secret National Security Agency wiretapping program, that may have helped thwart a planned terror attack aboard U.S.-bound flights from London last week.

Clinton adviser Howard Wolfson deemed the ad factually inaccurate and said, "Mr. Spencer's history of making wild-eyed angry falsehoods like these are among the many reasons why no one takes him or his campaign seriously."

In the ad, images of newspaper headlines fly across the screen, describing the terror plot targeting the airliners. A photo of Clinton is then paired with a photo of bin Laden.

"Senator Hillary Clinton opposed the Patriot Act and the NSA program that helped stop another 9/11. She'd leave us vulnerable," the narrator says.

Spencer spokesman Rob Ryan defended the ad.

"The ad speaks for itself," he said. "It's about the failure of Senator Clinton to take proper action to defend the state in a time of war."

Clinton, considered a potential presidential candidate in 2008, voted for the Patriot Act, which vastly expanded the federal government's ability to track terror suspects, in 2001.

Last year, she was part of a Democrat-led filibuster that forced Republicans to accept modest curbs on the government's power to investigate suspects. Once those modifications were made, most Senate Democrats, including Clinton, voted to renew expiring sections of the Patriot Act.

Spencer is competing with former Reagan-era Pentagon official Kathleen Troia "KT" McFarland for the GOP nomination to challenge the heavily favored Clinton. The primary is Sept. 12.